(a) Technical Field
Exemplary embodiments of the invention relate to an output current estimating method and a power supply device using the same.
(b) Description of the Related Art
An output current flowing to a secondary side is estimated based on a peak of a current flowing to a power switch, a discharge period during which a current flows to a rectification diode in the secondary side, and a switching cycle of the power switch. For example, the output current is estimated based on (peak of current)*(discharge period)/(switching cycle).
However, a substantial output current is reduced by a current flowing to a snubber circuit provided in a primary side. The amount of output current reduced due to the current flowing to the snubber circuit is not reflected to the equation of (peak of current)*(discharge period)/(switching cycle).
Thus, an error between the estimated output current and a substantial output current occurs.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.